Measurement of the Coherence of a Bose-Einstein Condensate

E. W. Hagley; L. Deng; M. Kozuma; M. Trippenbach; Y. B. Band; M. Edwards; M, Doery; P. S. Julienne; K. Helmerson; S. L. Rolston; W. D. Phillips

doi:10.1103/PhysRevLett.83.3112

Measurement of the Coherence of a Bose-Einstein Condensate

E. W. Hagley, L. Deng, M. Kozuma, M. Trippenbach, Y. B. Band, M. Edwards, M, Doery, P. S. Julienne, K. Helmerson, S. L. Rolston, and W. D. Phillips

Phys. Rev. Lett. 83, 3112 – Published 18 October 1999

Abstract

We present experimental and theoretical studies of the coherence properties of a Bose-Einstein condensate (BEC) using an interference technique. Two optical standing wave pulses of duration 100 ns and separation $Δ t$ are applied to a condensate. Each standing wave phase grating makes small copies of the condensate displaced in momentum space. The quantum mechanical amplitudes of each copy interfere, depending on $Δ t$ and on spatial phase variations across the condensate. We find that the behavior of a trapped BEC is consistent with a uniform spatial phase. A released BEC, however, exhibits large phase variation across the condensate.

Received 2 June 1999

DOI:https://doi.org/10.1103/PhysRevLett.83.3112

Authors & Affiliations

E. W. Hagley¹, L. Deng¹, M. Kozuma^1,*, M. Trippenbach^2,†, Y. B. Band², M. Edwards³, M, Doery¹, P. S. Julienne¹, K. Helmerson¹, S. L. Rolston¹, and W. D. Phillips¹

¹National Institute of Standards and Technology, 100 Bureau Drive Stop 8424, Gaithersburg, Maryland 20899-8424
²Departments of Chemistry and Physics, Ben-Gurion University of the Negev, Beer-Sheva, Israel 84105
³Department of Physics, Georgia Southern University, Statesboro, Georgia 30460-8031

^*Current address: Institute of Physics, Tokyo University, Tokyo 153-8902, Japan.
^†Permanent address: Institute of Experimental Physics, Optics Division, Warsaw University, ul. Hoza 69, Warsaw 00-681, Poland.